Ladle maintenance safety cage

ABSTRACT

A maintenance safety cage for ladles used in dispensing molten metal wherein the cage is lowered into the ladle which is still hot after having discharged all of the metal therein into molds. The cage is heat insulated and is used for replacing the usual stopper rod and valve plugs and repairing the nozzle in the bottom of the ladle. The cage has a stopper well which extends from the top to about the midpoint thereof and the well has a movable cover located at its bottom for opening and closing the well. The cover is hinged to a wall of the well and is movable to open position by a chain which passes through an opening in the wall and extends upwardly through a pipe-like conduit. The conduit operates to control the angle of pull upon the cover so as to hold it firmly against the wall of the well without creating any off-set pulling force and where it will minimize any scraping of the refractory around the stopper rod as the cage is being lifted out of the ladle.

United States Patent [191 Reighart Jan. 14, 1975 LADLE MAINTENANCE SAFETY CAGE [76] Inventor: June H. Reighart, 6809 Mayfield Rd., Mayfield Heights, Ohio 44124 [22] Filed: Oct. 11, 1972 21 Appl. No.: 296,637

[52] US. Cl 164/152, 222/559, 266/1 R [51] Int. Cl B22d 41/10 [58] Field of Search 164/335, 152; 49/347, 381,

Primary Examiner-Robert D. Baldwin Attorney, Agent, or Firm-Teare, Teare & Sammon [57] ABSTRACT A maintenance safety cage for ladles used in dispensing molten metal wherein the cage is lowered into the ladle which is still hot after having discharged all of the metal therein into molds. The cage is heat insu lated and is used for replacing the usual stopper rod and valve plugs and repairing the nozzle in the bottom of the ladle. The cage has a stopper well which extends from the top to about the midpoint thereof and the well has a movable cover located at its bottom for opening and closing the well. The cover is hinged to a wall of the well and is movable to open position by a chain which passes through an opening in the wall and extends upwardly through a pipe-like conduit. The conduit operates to control the angle of pull upon the cover so as to hold it firmly against the wall of the well without creating any off-set pulling force and where it will minimize any scraping of the refractory around the stopper rod as the cage is being lifted out of the ladle.

6 Claims, 5 Drawing Figures PATENTEU JAN 1 4l975 sum 1 OF 2 3.860.0 JAN 1 4191s PATWEU sum 2 BF 2 LADLE MAINTENANCE SAFETY CAGE BACKGROUND OF THE INVENTION The invention relates to cages adapted to be temporarily placed within a ladle, such as is used for receiving molten metal from an open hearth or electric furnace and pouring the same into ingot molds or the like, the cage being designed to shield the workman from the intense heat of the ladle during the time he is replacing the pouring nozzle in the ladle and setting the stopper rod therein.

It is common practice in steel mills to pour molten steel from an open hearth or electric furnace, into a ladle of the type having a bottom nozzle, for pouring the molten metal into ingot molds. The nozzle is of refractory material, and is used as a valve, being closed by inserting therein the end of a stopper rod, which extends up to the top of the ladle and is connected to a gooseneck, through which the stopper rod is raised out of engagement with the nozzle when it is desired to open the nozzle to discharge molten metal from the ladle into a mold.

The stopper rod is provided with a graphite stopper at its lower end, and the entire length of the rod is lined with refractory material. Both the refractory nozzle and the refractory lining of the stopper rod burn out and must be replaced.

The closest prior art of which applicant is aware is US. Pat. No. 2,908,055 granted to him on Oct. 13, 1959.

SUMMARY OF THE INVENTION Safety cages constructed as illustrated in the aforesaid patent have been extensively sold by applicants company and have proven so practical in the steel industry as to warrant not only increased sale over the years but considerable repeat business.

However, in practice, careless initial placement of the cage within the ladle often failed to properly align its working area with the area of the ladle being repaired.

Furthermore, careless offset vertical placement of the rebuilt stopper rod assembly within the somewhat limited working area indirectly resulted in damage to its readily friable refractory stopper rod head and rod sleeves.

The rebuilt stopper rod is generally conveyed to the safety maintenance cage (from the rebuilding area) by being hung or suspended from a hook on an overhead crane and it is readily conceivable that some swing and- /or sway to this somewhat lengthy hung assembly is quite frequent. Thus, unless this sway is corrected as it enters the confined working area of the cage, the assembly will strike the walls of the working area hereinafter referred to as the well.

This has been corrected by ancillary equipment connected to the cage, as will be described below, so that during vertical lowering of the rebuilt stopper rod assembly into proper position within the well and/r subsequent vertical removal of the safety cage from within the ladle, no damage to said properly positioned assembly is liable to occur.

Damage, however slight to the relatively soft stopper sleeves and stopper head necessitate removal of the assembly and replacement of any refractories that have become scratched, nicked or broken. This removal and partial rebuild becomes a time consuming factor as the ladle is generally needed for prompt refilling with molten metal which moves out of refining furnaces on a pretty much established schedule.

The scratched or nicked stopper head means it fails to properly seat with the refractory nozzle in the bottom of the ladle, resulting in leaky or running hot metal which cannot be tolerated in teeming of molten metals from ladles to molds positioned therebeneath.

Nicked or broken refractory sleeves result in overheating and early failure ofthe (central) steel rod which not only supports, at its lower end, the refractory stopper head but also the rod surrounding refractory sleeves.

Therefore, it is one of the prime objects of this invention to provide auxiliary features to this ladle maintenance safety cage which will prevent stopper rod assemblies from becoming damaged during or after being inserted into position within the restricted confines of the stopper rod setting well within the safety cage.

Another object is to minimize the time necessary to replace stopper rod assemblies and ladle nozzles without damage to the stopper rod assemblies, in particular.

Still another object is to gain more working area within the stopper rod setting well without sacrificing any propr convenience.

BRIEF DESCRIPTION OF THE DRAWINGS By way of example, a preferred embodiment of the improved ladle maintenance safety cage is illustrated in the accompanying drawings in which:

FIG. 1 is a front view of a ladle maintenance safety cage outside a ladle:

FIG. 2 is a longitudinal sectional view of the ladle maintenance cage located within a ladle and taken on a plane indicated by the line 22 in FIG. 1:

FIGS. 3 and 4 are sections taken on planes indicated by the lines 3-3 and 4-4 respectively in FIG. 1, and

FIG. 5 is a vertical sectional view through a portion of the cage taken on the line 5-5 in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, in which similar parts are designated by similar numerals throughout the several views, a conventional ladle for molten metal is shown, comprising an outer metallic shell 10 and an inner refractory lining 11, upon the side walls and bottom of the ladle.

The ladle is provided with the usual refractory nozzle 12, located through the bottom wall of the ladle adja' cent a side wall thereof, as in usual and well known practice. The usual stopper rod, for closing the nozzle 12, is indicated generally at 13, and extends vertically through the ladle from the top to the bottom thereof. As is usual practice, this stopper rod may comprise a metal rod 14, having the conical stopper 15, of graphite or the like, attached to its lower end, the entire length of the metal rod 14, within the ladle, being protected by refractory lining members or spools l6 strung upon the metal rod.

The upper end of the stopper rod is adapted to be attached to the usual gooseneck 17, the outer end of which is attached to the vertical sliding rod 18, slidable within the tubular guide 18a, and adapted to be raised by the manually operated lever 19, for lifting the stopper rod out of engagement with the nozzle 12, in order to discharge molten metal from the ladle.

All of the above may be of conventional ladle construction, and form no part of the present invention, which is concerned only with the ladle maintenance cage by means of which the conventional nozzle and stopper rod of the ladle may be removed and replaced in a minimum of time, and with complete comfort and safety for the workman immediately after a heat has been discharged from the ladle.

Reference is now made to the ladle maintenance safety cage. This cage comprises a substantially cylindrical metallic cage of substantially the same height as the ladle, and of proper diameter to permit lowering the cage into the ladle, as best shown in FIG. 2.

A vertical stopper rod setting well 21 is formed in one side of the cage and extends from the top to a point 45 substantially midway of the cage, and an access door 22 is located directly beneath the well and terminates at a point spaced from the bottom of the cage. The well is formed by two vertical walls 46 and 47 which extend inwardly and diagonally from the cage wall and meet in a vertical line 48. The walls thus form a pocket for receiving the stopper rod and for guiding the cage as it is being moved into and out of the ladle.

The door opening is of the same width as the well, and is continued to the bottom of the cage, providing a nozzle well as indicated at 23, where it communicates with the working notch 24 in the bottom of the cage, said opening being located below and in alignment with the stopper rod setting well.

The access door is hinged at one side of the door opening, as indicated at 25, and provides for placing clay, nozzles, tools, etc., in the cage while the cage is on the pit floor, and before it is placed within the ladle. Thus, the workman has nothing to carry with him, into or out of the cage in order to perform his work in replacing the nozzle and stopper rod in the ladle.

The door swings inward to open position entirely clearing the stopper rod setting well, and is provided at its swinging edge with latch means 26 for latching it in closed position. Latch means 50 within the cage hold the door in open position. Thus, the door, when open, forms no obstruction within the cage, which might interfere with the removal of the burned-out stopper rod or the setting of a new stopper rod in the ladle.

A cover 27 is hinged to the lower edge of the wall 47, as indicated at 51, and normally hangs in horizontal position adjacent the top of the door, thus closing the lower end of the stopper rod setting well 21, as shown in FIGS. 1 and 3, when the door 22 is in closed position. The cover 27, however, is adapted to be swung upwardly during the maintenance and repair operation on the stopper rod, but the difficulty heretofore has been to raise the cover adequately from a position inside the cage and preferably from a position adjacent the top of the cage. In practice, it was found that the cover remains as much as eight to ten degrees away from the wall in the open position. In such position, the stopper rod assembly quite often is struck by the partially open cover, which results in scratches and fractures in the refractory, which cannot be tolerated.

The present invention enables the cover to be swung a full 90 to a vertical position against the wall 47 of the well, by providing an opening 55 in the wall into which the lug 53 extends. This allows the cover to be pulled against the wall of the well and minimizes the danger of scraping the stopper rod refractory as the cage is being lifted out of the ladle.

To accomplish the aforegoing degree of opening the chain 52 passes through a pipe 56 which, as shown in FIG. 5, has a lower portion 57 extending diagonally upwardly from the opening 55, and another portion 58 extending vertically upwardly and serving as a guide for -the chain. Thus, the chain can be of indeterminate length and if desired can be detachably connected to a retainer 59 adjacent the top of the cage. Preferably, the lower portion of the pipe extends upwardly from the wall 47 at about an angle of 45.

The foregoing arrangement enables the chain to pass through the wall of the well and to be manipulated for raising the cover without creating any offset pulling force, which would be apt to prevent the cover from lying against the well or being parallel to it. Thus, when the cage is lifted from the ladle or when a new stopper rod assembly is lowered into the well any damage to the refractories on the rebuilt stopper rod is minimized.

An inturned, angular flange 30 is provided at the upper end of the metal shell 20 of the cage, and also extends around the upper end of the well 21. Similar flanges 31 and 32 respectively are provided at the lower end of the well 21, and around the door opening and nozzle well 23 and working notch 24, forming brick-retaining flanges around all openings of the shell, to provide for the installation of a lightweight insulating brick lining within the shell, as indicated at 33.

In order to provide safe entrance and exit for the workman, to and from the interior of the cage, an approach platform 34 is attached to the upper end of the cage and extends radially therefrom, as shown in FIG. 1.

Hand rails 35 are located on each side of the approach platform, at suitable height to be grasped by a workman walking upon said platform. A grab bar 36 is located at the outer end of the platform for engagement by hooks or the like on the upper end of a ladder which may be placed upon the tapping platform of the steel plant, to permit the workman to climb up to the approach platform of the cage.

A bail 37 may be located at the open upper end of the cage, for engagement by the hook of a crane, to permit a craneman to pick up the cage from the pit floor, or other location, and place it within the ladle. The cage should be positioned within the ladle as shown in FIG. 2 with the stopper rod 13 of the ladle received in the stopper rod well 21, and the nozzle well 23 and working notch 24 located around the ladle nozzle 12, so that the workman located upon the floor of the cage may have easy access to the nozzle 12 and adjacent portion of the ladle, through said nozzle well 23 and working notch 24.

A stopper rod setting platform 38 is located within the cage at a suitable height therein to permit a workman standing on the platform to disconnect the old burned out stopper rod from the gooseneck l7 and attach a new stopper rod thereto. This platform extends about halfway across the cage from the side thereof to which the approach platform 34 is attached, and terminates at a point spaced from the opposite side of the cage.

A hand-rail 39 is located across the upper portion of the cage, on the side thereof opposite to the stopper rod setting well 21, and at a suitable height above the platform 38 convenient to a workman standing upon said platform. A short ladder 40 is attached to the inner wall of the cage and extends down from the inner end of the approach platform 34 to the stopper rod setting platform 38.

At a point opposite to the short ladder 40, a long ladder 41 is mounted upon the inner wall of the cage and extends from the open upper end of the cage to the bottom wall thereof.

A hand-rail 42 is located within the cage adjacent to the upper portion of the ladder 41 and upon the opposite side thereof from the hand-rail 39. The hand-rail 42 extends from the inner wall of the cage to the adjacent wall of the stopper rod setting well 21.

In using the above described cage, the necessary tools and materials are placed within the cage, through the access door 22. The cage is then picked up by a crane and lowered into the ladle, being positioned therein so that the nozzle well 23 and working notch 24 of the cage expose the nozzle area of the ladle therethrough, sa shown in FIG. 2.

The workman may then hook the upper end of a ladder onto the grab bar 36, at the outer end of the approach platform 34, and enter the cage by climbing such ladder and then walking over the approach platform and climbing down the short ladder 40, onto the stopper rod setting platform 38.

While standing on the platform 38, the workman then disconnects the old, burned out stopper rod from the gooseneck l7, and the old stopper rod is removed by the crane. Then the workman steps from the platform 38, onto the long ladder 41, and descends the same to the bottom of the cage, where he may then close and latch the access door 22, from the interior of the cage, in order to further protect himself from the intense heat of the ladle at this point. As a further protection against the heat of the ladle, the workman may swing the cover 27 down into horizontal position, closing the lower end of the stopper-rod setting well 21, as indicated in FIG. 1.

The workman in the bottom of the cage is thus completely protected from the heat of the ladle, and in actual practice it has been found that there is a downdraft of air through the cage, so that the workman within the cage is actually cooler in this position than when out in the slag pit or up on the tapping platform.

Thus, the workman may work in complete comfort while removing the burned out nozzle from the ladle and cementing a new nozzle therein. Upon completion of his work upon the nozzle, the workman raises the cover 27 into position against the wall 47 of the well and unlatches and opens the door 22 swinging it back so that it clears the well as shown in dotted lines in FIG. 5.

Then the workman climbs the ladder 41 to the stopper rod setting platform 38. The craneman then lowers a new stopper rod into the cage and the workman within the cage sets the new stopper rod and connects it to the gooseneck 17, from his completely safe and comfortable position on the platform 38, and his work is completed.

After the workman has climbed the short ladder 40 and departed from the cage, via the platform 34, the craneman may lift the cage from within the ladle, and the ladle, which is still hot from the previous heat of metal, is again ready for use, since the ladle nozzle was replaced under conditions of high ladle temperature, so that the new nozzle cement will dry almost immediately.

It will thus be apparent that this improved ladle maintenance safety cage overcomes the disadvantages and difficulties of usual practice in replacing burned out nozzles and stopper rods in ladles, permitting these repairs to be made immediately after pouring steel from the ladle, without the necessity of any cooling off period, and with complete comfort and safety for the workman. Thus, a ladle may be returned to use only a few minutes after a heat has been poured therefrom, and while it is still hot enough to have no deleterious effect upon hot metal which may again be poured into it from a furnace.

I claim:

1. A ladle maintenance safety cage for protecting a human operator from the heat of a ladle used for molten metal and having a nozzle in its bottom and a stop per rod controlling said nozzle, said cage comprising,

a steel shell adapted to be inserted into said ladle,

a heat insulation lining within said shell,

a vertical opening in one side of said cage extending from the top of said cage to the bottom of said cage,

a stopper rod setting well in said one side of said cage and adapted to accommodate the stopper rod in said ladle,

said well extending from the top of said cage to a point spaced from the bottom thereof, and comprising spaced vertical side walls extending inwardly from opposite edges of said vertical opening,

the lower portion of said vertical opening forming an access door opening extending from the lower end of said well to the bottom of said cage,

a working notch in the bottom of said cage communi eating with the lower end of said vertical opening and providing means through which an operator within said cage may have access to said nozzle in said ladle,

an access door mounted in said door opening including a hinge along a vertical edge thereof pivotally connecting said access door to said shell to enable said access door to be swung inwardly into said shell,

said access door extending from the lower end ofsaid well to a point spaced above the bottom edge of said cage,

a cover at the bottom of said well, said cover being hinged to one of the walls of said well and being adapted to be swung downwardly to a horizontal position to close the lower end of said well,

means connected to said cover for maintaining it while in the fully opened position close to and parallel to the vertical side wall to which it is hinged,

said hinge on said access door being offset from the adjacent vertical edge of said access door and offset from said shell whereby said access door is disposed entirely within said shell and entirely clears said stopper rod setting well when said access door is swung to its open position to avoid any obstruction within said cage which might interfere with the removal of a burned-out stopper rod or the setting of a new stopper rod in said ladle,

said cover is hinged adjacent one edge to said one wall of said well adjacent to the bottom edge of said one wall,

said wall to which said cover is hinged has an opening,

said means connected to said cover for maintaining it while in the fully opened position comprises a flexible member connected to said cover at a point remote from said hinged edge, and

said flexible member extends through said opening and upwardly being accessible to an operator at a point near the top of said cage enabling said cover to be raised by said operator into a positioning in contact with or close proximity to said one wall from a position near the top of said cage.

2. A ladle maintenance safety cage according to claim 1 wherein,

the walls of the well form a V-shaped trough for receiving a stopper rod and, wherein a conduit within the cage has one end in communication with said opening in said one of the well walls and wherein,

said flexible member comprises a chain passing through the conduit and is guided thereby.

3. A ladle maintenance safety cage according to claim 2 wherein,

the conduit has a lower portion whichextends diagonally upwardly for a portion of its length and has an upper portion which extends vertically upwardly for the remaining portion of its length.

4. A ladle maintenance safety cage according to claim 1, including,

latch means mounted within said shell,

another latch means mounted on the vertical edge of said door remote from said hinged edge for latching connection of said access door with said latch means within said shell to hold said door in the open position.

5. A ladle maintenance safety cage for protecting a human operator from the heat of a ladle used for molten metal and having a nozzle in its bottom and a stopper rod controlling said nozzle, said cage comprising,

a steel shell adapted to be inserted into said ladle,

a heat insulation lining within said shell, there being a vertical opening in one side of said cage extending from the top of said cage to the bottom thereof,

a stopper rod setting well in said one side of said cage and adapted to accommodate the stopper rod in said ladle,

said well extending from the top of said cage to a point spaced from the bottom thereof, and comprising spaced vertical side walls extending in wardly from opposite edges of said vertical openmg,

the lower portion of said vertical opening forming an access door opening extending from the lower end of said well to the bottom of said cage,

a working notch in the bottom of said cage communicating with the lower end of said vertical opening and providing means through which an operator within said cage may have access to said nozzle in said ladle,

an access door mounted in said door opening including a hinge along a vertical edge thereof pivotally connecting said access door to said shell to enable said access door to be swung inwardly into said shell,

said access door extending from the lower end of said well to a point spaced above the bottom edge of said cage,

a cover at the bottom of said well, said cover being hinged to one of the walls of said well and being adapted to be swung downwardly to a horizontal position to close the lower end of said well,

said hinge on said access door being offset from the adjacent vertical edge of said access door and offset from said shell whereby said access door is disposed entirely within said shell and entirely clears said stopper rod setting well when said access door is swung to its open position to avoid any obstruction within said cage which might interfere with the removal of a burned-out stopper rod or the said setting of a new stopper rod in the ladle, and

means accessible from a point adjacent the top of said cage and connected to said cover for maintaining it while in the fully open position close to and parallel to said vertical side wall to which it is hinged.

6. A ladle maintenance safety cage for protecting a per rod controlling said nozzle, said cage comprising,

a steel shell adapted to be inserted into said ladle,

a heat insulation lining within said shell,

a vertical opening in one side of said cage extending from the top of said cage to the bottom of said cage,

a stopper rod setting well in said one side of said cage and adapted to accommodate the stopper rod in said ladle,

said well extending from the top of said cage to a point spaced from the bottom thereof, and comprising spaced vertical side walls extending in wardly from opposite edges of said vertical opening,

the lower portion of said vertical opening forming an access door opening extending from the lower end of said well to the bottom of said cage,

a working notch in the bottom of said cage communicating with the lower end of said vertical opening and providing means through which an operator within said cage may have access to the nozzle in said ladle,

an access door mounted in said access door opening including a hinge along a vertical edge thereof pivotally connecting said access door to said shell to enable said access door to be swung inwardly to said shell,

said access door extending from the lower end of said well to a point spaced above the bottom edge of said cage,

a cover at the bottom of said well, said cover being hinged to one of the walls of said well and being adapted to be swung downwardly to a horizontal position to close the lower end of said well,

means connected to said cover for maintaining it while in the fully opened position close to and parallel to the vertical side wall to which it is hinged,

said hinge on said access door being offset from the adjacent vertical edge of said access door and offset from said shell whereby the access door is disposed entirely within said shell and entirely clears the stopper rod setting well when the access door is swung to its open position to avoid any obstruction within said cage which might interfere with the removal of a burned-out stopper rod or the setting of a new stopper rod in the ladle,

said cover is hinged to said one wall of said well adjacent to the bottom edge of said one wall,

it while in the fully open position comprises a flexible member connected to said lug and extending upwardly and assessable to an operator at a point near the top of said cage. 

1. A ladle maintenance safety cage for protecting a human operator from the heat of a ladle used for molten metal and having a nozzle in its bottom and a stopper rod controlling said nozzle, said cage comprising, a steel shell adapted to be inserted into said ladle, a heat insulation lining within said shell, a vertical opening in one side of said cage extending from the top of said cage to the bottom of said cage, a stopper rod setting well in said one side of said cage and adapted to accommodate the stopper rod in said ladle, said well extending from the top of said cage to a point spaced from the bottom thereof, and comprising spaced vertical side walls extending inwardly from opposite edges of said vertical opening, the lower portion of said vertical opening forming an access door opening extending from the lower end of said well to the bottom of said cage, a working notch in the bottom of said cage communicating with the lower end of said vertical opening and providing means through which an operator within said cage may have access to said nozzle in said ladle, an access door mounted in said door opening including a hinge along a vertical edge thereof pivotally connecting said access door to said shell to enable sAid access door to be swung inwardly into said shell, said access door extending from the lower end of said well to a point spaced above the bottom edge of said cage, a cover at the bottom of said well, said cover being hinged to one of the walls of said well and being adapted to be swung downwardly to a horizontal position to close the lower end of said well, means connected to said cover for maintaining it while in the fully opened position close to and parallel to the vertical side wall to which it is hinged, said hinge on said access door being offset from the adjacent vertical edge of said access door and offset from said shell whereby said access door is disposed entirely within said shell and entirely clears said stopper rod setting well when said access door is swung to its open position to avoid any obstruction within said cage which might interfere with the removal of a burned-out stopper rod or the setting of a new stopper rod in said ladle, said cover is hinged adjacent one edge to said one wall of said well adjacent to the bottom edge of said one wall, said wall to which said cover is hinged has an opening, said means connected to said cover for maintaining it while in the fully opened position comprises a flexible member connected to said cover at a point remote from said hinged edge, and said flexible member extends through said opening and upwardly being accessible to an operator at a point near the top of said cage enabling said cover to be raised by said operator into a positioning in contact with or close proximity to said one wall from a position near the top of said cage.
 2. A ladle maintenance safety cage according to claim 1 wherein, the walls of the well form a V-shaped trough for receiving a stopper rod and, wherein a conduit within the cage has one end in communication with said opening in said one of the well walls and wherein, said flexible member comprises a chain passing through the conduit and is guided thereby.
 3. A ladle maintenance safety cage according to claim 2 wherein, the conduit has a lower portion which extends diagonally upwardly for a portion of its length and has an upper portion which extends vertically upwardly for the remaining portion of its length.
 4. A ladle maintenance safety cage according to claim 1, including, latch means mounted within said shell, another latch means mounted on the vertical edge of said door remote from said hinged edge for latching connection of said access door with said latch means within said shell to hold said door in the open position.
 5. A ladle maintenance safety cage for protecting a human operator from the heat of a ladle used for molten metal and having a nozzle in its bottom and a stopper rod controlling said nozzle, said cage comprising, a steel shell adapted to be inserted into said ladle, a heat insulation lining within said shell, there being a vertical opening in one side of said cage extending from the top of said cage to the bottom thereof, a stopper rod setting well in said one side of said cage and adapted to accommodate the stopper rod in said ladle, said well extending from the top of said cage to a point spaced from the bottom thereof, and comprising spaced vertical side walls extending inwardly from opposite edges of said vertical opening, the lower portion of said vertical opening forming an access door opening extending from the lower end of said well to the bottom of said cage, a working notch in the bottom of said cage communicating with the lower end of said vertical opening and providing means through which an operator within said cage may have access to said nozzle in said ladle, an access door mounted in said door opening including a hinge along a vertical edge thereof pivotally connecting said access door to said shell to enable said access door to be swung inwardly into said shell, said access door extending from the lower end Of said well to a point spaced above the bottom edge of said cage, a cover at the bottom of said well, said cover being hinged to one of the walls of said well and being adapted to be swung downwardly to a horizontal position to close the lower end of said well, said hinge on said access door being offset from the adjacent vertical edge of said access door and offset from said shell whereby said access door is disposed entirely within said shell and entirely clears said stopper rod setting well when said access door is swung to its open position to avoid any obstruction within said cage which might interfere with the removal of a burned-out stopper rod or the said setting of a new stopper rod in the ladle, and means accessible from a point adjacent the top of said cage and connected to said cover for maintaining it while in the fully open position close to and parallel to said vertical side wall to which it is hinged.
 6. A ladle maintenance safety cage for protecting a human operator from the heat of a ladle used for molten metal and having a nozzle in its bottom and a stopper rod controlling said nozzle, said cage comprising, a steel shell adapted to be inserted into said ladle, a heat insulation lining within said shell, a vertical opening in one side of said cage extending from the top of said cage to the bottom of said cage, a stopper rod setting well in said one side of said cage and adapted to accommodate the stopper rod in said ladle, said well extending from the top of said cage to a point spaced from the bottom thereof, and comprising spaced vertical side walls extending inwardly from opposite edges of said vertical opening, the lower portion of said vertical opening forming an access door opening extending from the lower end of said well to the bottom of said cage, a working notch in the bottom of said cage communicating with the lower end of said vertical opening and providing means through which an operator within said cage may have access to the nozzle in said ladle, an access door mounted in said access door opening including a hinge along a vertical edge thereof pivotally connecting said access door to said shell to enable said access door to be swung inwardly to said shell, said access door extending from the lower end of said well to a point spaced above the bottom edge of said cage, a cover at the bottom of said well, said cover being hinged to one of the walls of said well and being adapted to be swung downwardly to a horizontal position to close the lower end of said well, means connected to said cover for maintaining it while in the fully opened position close to and parallel to the vertical side wall to which it is hinged, said hinge on said access door being offset from the adjacent vertical edge of said access door and offset from said shell whereby the access door is disposed entirely within said shell and entirely clears the stopper rod setting well when the access door is swung to its open position to avoid any obstruction within said cage which might interfere with the removal of a burned-out stopper rod or the setting of a new stopper rod in the ladle, said cover is hinged to said one wall of said well adjacent to the bottom edge of said one wall, said wall to which said cover is hinged has an opening and wherein, said cover has a lug which is adapted to enter said opening when the cover is raised to the fully opened position, and said means connected to said cover for maintaining it while in the fully open position comprises a flexible member connected to said lug and extending upwardly and assessable to an operator at a point near the top of said cage. 